Desuperheating deaerating heater



Dec. 13, 1966 Filed Oct. 12. 1960 R. K. STENARD DESUPERHEATING DEAERATING HEATER 5 Sheets-Sheet 1 STAGE HEATERS CONDENSER I4\ DEAERATOR STORAGE REGULATING VALVES 27 TANK INVENTOR TuRamE ROBERT K. STENARD.

STEAM GENERATOR 26 1 BY 12 ATTORNEY Dec. 13, 19%6 R. K. STENARD 3,291,105

DESUPERHEATING DEAERATING HEATER Filed Oct. 12, 1960 5 Sheets-Sheet 2 N i 8; q 9 9 PO LL.

0) INVENTOR; E ROBERT K. STENARD.

ATTORNEY Dec. 13, 1966 R. K. STENARD 3,291,105

DESUPERHEATING DEAERATING HEATER Filed Oct. 12. 1960 5 Sheets-$heet 3 FIG. 6.

INVENTOR;

ROBERT K. STENAR D.

ATTORNEY Dec. 13, 1966 R. K. STENARD EQQLWS I DESUPERHEATING DEAERATING HEATER Filed on 12. 1960 5 Sheets-Sheet 4 FIG. IO.

INVENTOR;

I BY XW -f ATTORNEY ROBERT K. STENARD.

Dec. 13, 1966 R. K. STENARD 9 DESUPERHEATING DEAERATING HEATER Filed Oct. 12, 1960 1 5 Sheets-Sheet 5 FIG. I5

INVENTOR; ROBERT K. STENARD.

BY r: w?

ATTORNEY nited States Patent ()fiice 3,29Lld Patented Dec. 13, 1966 3,291,105 DESUPERHEATING DEAERATING HEATER Robert K. Steuard, Garden (City, N.Y., assignor to Union Tank Car (Iompany, Chicago, llll., a corporation of New .Iersey Filed Oct. 12, 1960, Ser. No. 62,125 7 Claims. (Cl. 122-4tl6) This invention relates to an apparatus for desuperheating steam and deals particularly with an apparatus for reducing the temperature of steam in a closed steam circuit such as a power generating circuit when the turbine or other apparatus for which the steam is generated is suddenly cut off.

In steam power plants of the high pressure type, a closed steam cycle is usually employed. A large proportion of the steam which is generated is normally fed directly to turbines and most of the exhaust steam from the turbines is directed to a condenser where the steam is condensed. From the condenser, the condensate passes through a deaerating heater which removes air from the liquid and also acts to preheat it. Portions of the steam from the turbine are usually directed through bleed linm to intermediate regenerative stage heaters and to a deaerating heater which raises the temperature of condensate. From the deaerator, the water flows into a storage tank from which it is recirculated to the steam generator.

In certain types of systems, such as those employing an atomic reactor, difliculty is experienced when the turbine is cut off from the steam supply. In the event of an overload emergency, the turbine tends to overspeed and by means of an inlet control valve the supply of steam is cut off from the turbine. At the same time, the steam generator will continue to produce steam at a high rate. This creates a serious problem where it is difficult to reduce the heat source rapidly as in an atomic reactor where liquid sodium is used as the heating medium in the generator. Cooling water must continue to flow through the steam generator where it is evaporated into steam, in order to prevent injury to the genertor. If the output of the steam generator were vented to atmosphere for any length of time, the closed system would rapidly run out of water. The only practical solution for this difiiculty is to condense the steam produced by the generator and to return the condensate to the system by recycling it.

When the turbine cuts out, the steam pressure from the generator may be reduced by a series of pressure regulating valves arranged in a by-pass line which is automatically opened when the turbine trips out. The objective is to return the steam to the main condenser where it will be condensed, sent back through the stage heaters, to the deaerator, and back to the boiler. This method involves the problem of disposing of a large quantity of high temperature steam which results when the pressure is reduced, since the temperature of the steam usually exceeds the limits acceptable to the condenser. One solution of the problem is to provide a standby condenser system which is used only in such an emergency, and through which the steam was bypassed. Such standby condenser systems are costly and space consuming.

It is, therefore, an object of the present invention to provide a means for desuperheating extremely large volumes of high temperature steam, and to eliminate the need for expensive standby equipment.

I have found that a conventional deaerating heater may be so reconstructed as to adapt it for desuperheating large quantities of clump steam. Once the steam has been desuperheated, it may be directed to a condenser and follow its normal cycle. My improved steam desuperheater and condensate deaerator adds little to the cost of the system and results in apparatus which functions efficiently in emergencies without a standby condenser or other special standby equipment.

Another object of the present invention is to provide a deaerator which utilizes water from a condenser to desuperheat large quantities of high temperature dump steam and to continuously deaerate both condensate heated by the dump steam and that heated by steam from a bleed line connected to the discharge of the turbine.

A further object is to provide in a deaerator a large elongated passage and chamber for the high temperature steam into which condensate is sprayed and then caused to flow in attenuated streams through a deaerator structure having a multiplicity of deaerating tray members between which deaerating steam is caused to flow. As the steam flows through the desuperheating chamber its temperature is lowered by the condensate sprays so that the steam is desuperheated and some of it is condensed and permitted to drain into the deaerator trays and then to the storage tank. The steam outlet of the desuperheating passage communicates with the condenser.

A feature of the present invention resides in the provision of baffies arranged in the desuperheating chamber and passage to direct the steam in a tortuous path through the condensate spray area.

A further feature of the present invention resides in the provision of a mist eliminator through which the steam must flow to reach the steam outlet of the deaerator with the result that the liquid entrained with the seam is separated from the steam and drained to the storage tank.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of the specification:

FIGURE 1 is a side elevational view of the deaerator and the storage tank, a portion of these units being broken away to show interior portions thereof;

FIG. 2 is a diagrammatic view of a steam system with which my apparatus may be employed;

FIG. 3 is a longitudinal vertical sectional view through the deaerator showing the general arrangement of parts therein;

FIG. 4 is a vertical cross sectional view taken on the line 44 of FIG. 3;

FIG. 5 is a cross sectional view taken on the line 55 of FIG. 3;

FIG. 6 is a longitudinal horizontal sectional view taken on the line 66 of FIG. 3;

FIG. 7 is an end elevational view of the deaerator and of a portion of the storage tank;

FIG. 8 is a cross sectional view taken on the line 8-8 of FIG. 3;

FIG. 9 is an elevational view showing certain of the steam baffles within the deaerator;

FIG. 10 is an elevational view showing additional steam baffles within the deaerator;

FIG. 11 is an elevational view showing baflles of another form;

FIG. 12 is a detail sectional View showing a fragmentary portion of one of the weir flanges and associated distributor pan members;

FIG. 13 is a fragmentary vertical sectional view taken approximately on the line 1313 of FIG. 6, showing a portion of the deaerating tray structure;

FIG. 14 is a fragmentary vertical sectional view taken approximately on the line 14-44- of FIG. 6, showing one of the steam impact plates and fragmentary portion of the shell, and

FIG. 15 is a perspective view showing other baffle elements which deflect the high temperature steam entering from the dump stream nozzle.

FIG. 2 of the drawings shows, diagrammatically, a

vcondenser.

r, a typical arrangement of my improved deaerator and de superheater in a steam system. Water from a storage tank is fed by a pump 11 to a steam generator 12 which evaporates the water and produces superheated steam. This steam is normally directed to a turbine 13 which converts much of the heat of the steam into mechanical energy. The steam exhaust conduit 14 from the turbine 13 leads to a condenser 15 where the major portion of the exhaust steam is condensed. From the condenser 15, the liquid is pumped, as by a pump 16, through stage heaters indicated at 17, 19 and 20 and is then conducted to a deaerator indicated generally by the numeral 21 wherein the condensate is deaerated and drained to the storage tank 10 from which it is recycled.

The stage heaters 17, 19 and 20 are heated by steam passing through bleed lines 22, 23 and 24, respectively, which are connected to the exhaust line 14. An additional bleed line 25 extends from the turbine exhaust to the deaerator 21 to heat the liquid while it is being deaerated. The manner in which this is accomplished will be later described in detail.

The inlet to the turbine is controlled by a three-port two-way valve 26 which is selectively operative to pass steam from the generator 12 to the turbine or to bypass it to pressure reducing valves 27 and a line 29 extending to the desuperheater-deaerator 21. This valve is preferably of the automatic, pressure responsive type adapted to by-pass steam to the pressure reducing valves and deaerator when overloading of the turbine causes a predetermined high pressure to be built up in the turbine inlet line.

In an overload emergency, the turbine 13 will overspeed and the valve 26 will trip to cut off the steam supply. Since the steam generator 12 is being heated by a source of heat which cannot be quickly cut off, the steam output of the generator must be disposed of quickly to prevent build up of excessive pressure in the system. Pressure regulator valves 27 are connected to the steam generator and are designed to reduce the pressure of the steam which is fed to the desuperheater-deaerator 21. These valves may be of the diaphragm type with a Wizard controller, e.g., a type 657-A valve manufactured by the Fisher Governor Company.

If the output of the steam generator is vented, the system will quickly run out of water causing extreme damage to the generator. For some installations a bypass line may be provided between the pressure regulators and the condenser 15 so that the steam can be condensed and recycled. However, when considerable time is required to reduce the temperature in the generator the temperature of the steam passing through the pressure regulator valves 27 exceeds the limits acceptable to the For such installations a standby condenser system capable of accepting this high temperature steam and returning it to the system has sometimes been employed. This solution of the problem necessitates a very substantial investment in equipment which is used only in emergencies and which is therefore economically wasteful.

According to the present invention the steam from the pressure regulator valves 27 passes through a conduit 29 to the deaerator 21. In the upper portion of this deaerator I provide a tortuous passage through a chamber 9 (FIG. 3) for the superheated steam wherein the steam is cooled by the sprays of condensate from the condenser 15. Thus the large volume of steam which passes through the pressure regulator valves is desuperheated in the chamber 9 and passes from the deaerator through a conduit 30 to the condenser 15 from which a portion of the cooled steam may be recycled in the usual manner.

As best shown in FIG. 3 of the drawings, the deaerator 21 includes a pressure chamber defined by an elongated cylindrical shell 31 having outwardly rounded ends 32 and 33. A vented condensate manifold 34 is formed in the upper portion of the shell 31. by a bottom panel 4. 35, closed end walls 37 and side walls 39 shown in FIG. 5. The side and end walls are welded or otherwise secured to the inner surface of the shell 31. An inlet nozzle 40 communicates with the interior of the manifold 34 and a deflector plate 42 is supported in spaced relation to the inner end of the nozzle 40 by mounting brackets 43.

A series of spray nozzles 44 extend through the bottom panel 35 of the manifold 34, these nozzles being spaced longitudinally and transversely of the manifold to distribute the concentrate sprays uniformly in the high temperature steam chamber 9 below panel 35. The bottom of the steam chamber 9 is formed by a multiplicity of horizontally disposed tray members as hereinafter described.

Banks of deaerator trays are mounted below the desuperheating chamber 9 on channels 45 which extend transversely across the lower portion of the shell 31 to support a tray frame indicated in general by the numeral 46. The deaerating trays are omitted from FIG. 3 to showthe frame 46 having vertically spaced horizontally extending bars 47 and longitudinally spaced vertical bars 49 welded or otherwise secured to the bars 47. At each end the frame 46 has horizontally extending bars 50 connecting the side frame members. A grating 51 rests upon the channels 45 to form the bottom of the deaerating tray assembly. The upper portion of the tray supporting frame 46 is connected to a transverse angle bar 52 which is secured at its ends to the shell 31. A similar transverse angle bar 53 is provided at the opposite end of the frame.

As shown in FIG. 5, a pair of elongated inwardly sloping pans 54- and 55 are secured along their outer edges to the shell 31 and extend to the top of the frame 46 where weir flanges 56 extend the entire length of the pans. The upper edges of the flanges 56 are disposed horizontally and formed with notches 59 (FIG. 12) which distribute water from the pans to horizontally extending tray members 57. The tray members 57 extend across the top of the frame 46 in spaced relation one to another. Thus the weir flanges 56 distribute water collected upon the pans 54 and 55 into both ends of the channel shaped tray members 57.

Condensate overflows the sides of the members 57 in thin streams and is caught in deaerating trays 60 mounted within the frame 46. As indicated in FIG. 5, three banks of deaerating trays 60 are provided within the frame 46. A fragmentary portion of the structure is shown in FIG. 13. Each bank of the deaerating trays 6G is preferably formed from a series of rectangular units disposed side by side and separated one from another by side plates 60a. These side plates are connected together in horizontally spaced relation by vertically spaced angle members 61. Spaced longitudinally extending channel shaped tray members 62, 63 and 64 are supported on the members 61 and the tray members of one layer are staggered relative to those of the next layer above and below so that the liquid which overflows one layer is caught by the members of the layer below and is finely divided as it is exposed to steam flowing along and between the several members 62, 63 and 64. During the exposure to the steam, oxygen and carbon dioxide gases are removed from the liquid by the steam. The steam is directed horizontally and longitudinally through the deaerating tray structure as hereinafter described.

Bleed steam is fed to the deaerator shell 31 by a nozzle '65 which enters the end '32 of the shell slightly above the level of the grating 51, the inner end of the nozzle being supported by a bracket 66. Dump steam is also delivered to the shell 31 through its end wall 32 by a nozzle 67. Such high pressure steam may be fed to the nozzle 67 from the pressure reducing valves 27 under control of valve 26 in the event the turbine cuts off or whenever an excess of high temperature steam is to be desuperheated. To protect the deaerator from the high temperature steam entering through the dump steam nozzle 67,

the portion of the deaerating tank adjoining this nozzle 67 is insulated. As indicated in FIG. 3, a semi-cylindrical shroud 69 is supported in spaced relation to the shell 31, and a baflie structure, best shown in FIG. 15, is disposed to separate the dump steam nozzle 67 from the bleed steam nozzle 65. The baflle structure indicated in general by the numeral 71 is supported by angles 71 which extend transversely of the shell 31 and are connected thereto.

Baffie structure 70 includes a panel 72 through which the nozzle 67 extends and angularly disposed side wings 73 and '74 fitting in spaced relation to the rounded end 32 of the shell 31. The edges 75 of the members 72, 73 and 7-1- fit Within the shroud 69 and are secured thereto. A generally horizontal bafiie member 76 is secured to the lower edges of the members 72, 73 and 74 and the member 7-6 is bent along a line 77 parallel to the axis of the shell 31 so that the upper surface of the member 76 is slightly concave. A vertical baffle member 79 is secured to the inner edge of the member 76 to extend upwardly therefrom and has ends which are fastened to the shell 31. As shown in FIGS. 3 and 15, a box shaped bafiie comprising a horizontal upper member 80, a parallel lower member 81 and connecting vertical sides 82 extends bet-ween the vertical bafiie member 79 and the end of the deaerator tray frame 46 to reverse the direction of the steam flowing from one deaerator tray bank to the next above. The upper bafiie member 30 is provided with laterally projecting Wings 83 which are upwardly and outwardly inclined to fit in contact with the ends of the pans 54 and 55. The end edges of the wings 83 are welded to the shell 31.

The baffle member 7 6 slopes inwardly and downwardly at a small angle to the horizontal and, as indicated in FIGS. 3 and 8, a generally J-shaped pipe 84 extends through the member 7-6 adjacent to the inner end thereof. This pipe 8 1 has a vertical portion 85 connected to the baffle member 76, a horizontal portion 86 extending transversely from the low end of the portion 85, and an upwardly extending open end portion 87. This I-shaped pipe 34 is an overflow pipe for draining water from the chamber above the baffle member 76 to water outlet chamber connected to the storage tank 10.

A perforated plate 89 is positioned inwardly of the inner end of the bleed steam pipe 65 to prevent the full force of the steam from being directed into the lower series of deaerating trays and to equalize the flow of steam through the width of the deaerating frame.

As shown in FIGS. 3 and 4, a transversely extending plate 90 closes the right end of the tray supporting frame 46 above the lower two tiers of trays and a rectangular extension of the steam passage at the right end of the lower tiers is formed by an upper plate 91, a lower plate 92, side plates 93 and an end panel 94 provided with an inspection door 95. This extension of the steam passage reverses the direction of flow at the right end of the bottom bank of deaerator trays. As indicated by arrows in FIG. 3, the deaerating steam is thus directed to the right through the lowermost bank of deaerating trays, then to the left through the intermediate bank of deaerating trays, then up through the boxlike ba'llle structure formed by the members '79, 80, 81 and 82, and then to the right through the uppermost bank of deaerating trays.

As further shown in FIGS. 3, 14 and 15, an impact plate 96 extends transversely across the shell 31 in spaced relation to the inner end of the dump steam nozzle 67 and has an arcuate outer edge welded to the inner surface of the shell 31. The plate 96 thus forms an end wall closure for the shroud 69 and has a flange 97 along its lower edge for reinforcement. Gusset plates 99 of approximately triangular form are secured as by welding to the plate 96 and shell 31. Impact plate 96 is also reinforced by spaced vertical ribs 100 which not only stiffen the impact plate but also function to minimize the deflection of steam laterally to the shell 31.

By the structural elements hereinbefore described, the

steam entering from nozzle 67 is deflected downwardly by the impact plate 96 and the direction of flow of the steam is changed by the baffle members 76 and 79, which direct the steam upwardly toward the top of the shell 31 and into the desuperheating chamber 9. Upon entering this chamber the steam is deflected toward the longitudinal center of the shell by a pair of opposed baflies 101 is shown in FIGS. 5 and 6. Thereupon the steam is directed first toward one side of the shell and then toward the other side by the longitudinally spaced baffles 102, 103 and 164 extending in planes which are perpendicular to the axis of the shell 31. These bafiies are similarly shaped, the baffles 102 and 104 being substantially identical, and the bafile 193 being similar but reversed. All of the baffles 101, 102, 103 and 104 have arcuate outer edges which are welded to the inner surface of the shell 31.

Another pair of opposed baffles 195, similar in shape to the bafiies 101, are secured to the inner surface of the shell 31 beyond the battle 1% in the direction of travel of the steam, being adapted to direct the steam toward the longitudinal center of the shell. Next in the direction of flow is a bafiie 1% extending transversely across the shell above the end of the tray supporting frame 46. As indicated in FIGS. 4 and ll, the baffle 11% extends across the central portion of the steam passage and has openings 107 adjacent to the inner surface of the shell 31 through which the steam mus-t flow. By this arrangement of baffies in the desuperheating chamber 9 I insure efficient and rapid desuperheating and conduction of the excess heat to the condensate sprays from the nozzles 44.

A mist eliminator element 1119 of conventional construction is angularly supported in the path of the steam from the openings 107, and an outlet conduit 110 communicates with the shell 31 through its end wall 33. This mist eliminator removes the greater portion of the moisture from the steam before it leaves the shell 31 through the outlet conduit 110. An impact plate 111 is mounted in spaced relation to the open end of the conduit 110.

Non-condensable gases such as oxygen and carbon dioxide are discharged from the deaerator shell through vents 112 of conventional construction and pressure relief valves may also be connected to the mist eliminator 109, or to the shell 31 itself, or to the steam outlet thereof. In preferred form, a condensate outlet conduit 113 connects the bottom of the shell 31 to the storage tank 10 and is protected by a hood and screen 114. The storage tank 10 may be protected by a flash preventer adjoining the conduit 113 and pressure equalizer connections 115 extending between the interior of the shell 31 and interior of the storage tank 10.

As hereinbefore more fully described, in operation, the shell 31 is supplied with condensate through the inlet nozzle 49 so that the manifold 34 is continuously filled with liquid under predetermined pressure. Spray nozzles 44 distribute the condensate as fine sprays uniformly throughout and crosswise of the desuperheating chamber 9 above the deaerating trays 60. The sprayed liquid, after cooling the steam in chamber 9, is collected in the horizontal tray members 57 and flows over the sides of these members into the upper layer of deaerating trays 60. The liquid overflows in attenuated streams from one tier of trays to the next below until it reaches the bottom of the shell 31 from which it flows through conduit 113 to storage tank 10.

During normal operation, bleed steam flows through the nozzle 65 and is distributed across the shell 31 by the perforated bafiie 89. The steam flows in the direction of the arrows indicated in FIG. 3 of the drawings, first toward one end of the deaerator and then toward the other end, finally passing upwardly between the water distributing tray members 57 to the chamber 9 from which it flows to the outlet conduit 110.

Steam flowing over and through the thin films of liquid removes entrapped oxygen and carbon dioxide and carries such .gases upwardly to vented chamber 8. The condensable gases are condensed, and the remaining gases are vented to atmosphere through the vents 112.

When flow of steam from the generator to the turbine or to other apparatus for utilizing the steam is suddenly cut olf, the steam is by-passed by operation of the valve 26 through the series of pressure reducing valves 27 and is conducted to the dump steam nozzle 67. This dump steam which may be superheated and under high pressure is directed in a tortuous path by the various baflies in the desuperheating chamber 9 where sprays from the nozzles 44 have sufficient cooling effect to cause some of the steam to be condensed and the remaining steam to be desuperheated. During this treatment, the steam may entrain fine condensate which is removed by the mist eliminator 109. The steam leaving the deaerating tank through the conduit 110 is at a suitable temperature and pressure to be received by the condenser. Thereafter, the condensate is pumped from the condenser to the inlet nozzle 40 thus completing the cycle of operation.

In the event that the superheat in the steam is not entirely removed, or in an emergency, pressure relief valves may be used to maintain the pressure at a safe level. In any event, my improved desuperheater and deaerator has sufficient capacity to desuperheat large quantities of steam in the spray chamber and to simultaneously condense some of the high temperature steam.

The utility of the present invention is not limited to closed circuit steam systems. In once through boiler systems there are no drums for the internal separation of water and steam and during start up and shut down periods, a mixture of steam and water is discharged from the steam generator. This mixture cannot be handled by the turbine and it is customary to install separator tanks externally to the boiler which separate the steam from the water. The steam is fed to the condenser and is returned to the water cycle. My desuper heating-deaerating heater is inherently useful as a separator in such once through units. Thus a mixture of steam and water may be fed into the unit through the nozzle 67 so that a major portion of the entrained water is separated by the bafiie 96 and the residual entrained water would be separated in the course of travel through the chamber 9 and mist eliminator 109. It is further evident that the present invention has utility in closed systems which do not include a turbine in the cycle. Thus the steam in the closed circuit may be used for any purpose such as apparatus for process treatment or heating, for example.

I claim:

1. A steam system comprising a steam generator, a steam-utilizing apparatus, a condenser, a desuperheaterdeaerator means and a condensate storage tank connected in series by conduit means in circuit, a steam bypass conduit means connected through a pressure responsive valve means to said conduit means interconnecting said steam-utilizing apparatus and said steam generator, said steam by-pass conduit means communicating with said desuperheater-deaerator means, said pres sure responsive valve means so constructed and arranged to permit the flow of steam from said steam generator to said steam-utilizing apparatus until the pressure of said steam exceeds a pre-determined pressure and then to direct said steam through said steam by-pass conduit to said desuperheater-deaerator means, said desuperheating-deaerator means comprising a tank having a deaerating zone and a desuperheating zone, said desuperheating zone being above said deaerating zone and communicating therewith, a deaerated water outlet connected to the bottom of said tank, means for spraying condensate from said condenser into said desuperheating zone, said deaerating zone being below said spraying means to receive said condensate from said high temperature steam zone, means for supplying steam to said deaerating zone, said steam by-pass conduit means communicating with said desuperheating zone and steam outlet means for removing steam from said desuperheating zone and said deaerating zone.

2. The steam system of claim 1 wherein said means for supplying steam to said deaerating zone is connected to said conduit means interconnecting said steam-utilizing apparatus and said condenser and said steam outlet means communicates with said condenser.

3. A steam system comprising a steam generator, a steam-utilizing apparatus, a condenser, a desuperheaterdeaerator means and a condensate storage tank connected in series by conduit means in circuit, a steam bypass conduit means connected through a pressure responsive valve means to said conduit means interconnecting said steam-utilizing apparatus and said steam generator, said steam by-pass conduit means communicating with said desuperheater-deaerator means, said pressure responsive valve means so constructed and arranged to permit the flow of steam from said steam generator to said steam-utilizing apparatus until the pressure of said steam exceeds a pre-determined pressure and then to direct said steam through said steam by-pass conduit to said desuperheater-deaerator means, said desuperheating-deaerator means comprising a tank containing a plurality of superimposed spaced deaerating trays forming a longitudinal zig-zag steam passage therebetwcen having first and second ends, a condensate outlet connected to the bottom of said tank, conduit means connecting said condensate outlet to said condensate storage tank, a condensate inlet connected to the top of said tank, conduit means connecting said condenser with said condensate inlet, means defining a desuperheating passage in said tank below said condensate inlet and above said deaerating trays, said steam by-pass conduit means communicating with one end of said desuperheating passage, a series of spray heads communicating with said condensate inlet and disposed to spray condensate into said desuperheating passage, said deaerating trays being disposed below said spray heads to receive condensate from said desuperheating passage, a steam bleed conduit means for supplying steam to said first end of said zig-zag steam passage, and steam outlet means communicating with the other end of said desuperheating passage and said second end of said zig-zag steam passage.

4. The steam system of claim 3 wherein said steam bleed conduit means is connected to said conduit means interconnecting said steam-utilizing apparatus and condenser and said steam outlet means communicates with said condenser.

5. The system of claim 3 wherein said desuperheaterdeaerator means has longitudinally spaced water distributing pans extending transversely above said trays for receiving condensate from said spray heads and distributing said condensate to said deaerating trays.

6. The steam system of claim 3 wherein said desuperheater-deaerator means includes downwardly and inward- 1y inclined pans extending along opposite sides of said tank and each having an inner edge terminating above said trays, a notched weir extending upwardly from each of said inner edges, water distributing means extending transversely between said pans above said trays to receive water from said weirs and to distribute water to said trays.

7. The steam system of claim 3 wherein said desuperheater-deaerator means has an impact plate disposed in said tank to deflect the steam from said steam by-pass conduit means downwardly and a first bathe means in the path of the downward movement of said steam to direct the steam in an upward direction, a pair of opposed bafiles longitudinally spaced from said impact plate extending inwardly from opposite sides of said tank to direct said steam toward the center of the tank, a second bafile near said steam outlet means to deflect steam toward the sides of the tank, and a series of longitudinally spaced bafiles between said pair of baflies and said second bafiie in said desuperheating passage, the batlles of said series alternately extending inwardly from opposite sides of said tank.

References Cited by the Examiner UNITED STATES PATENTS 316,297 4/1885 Rohan 261-148 1,473,449 11/1923 Stearns et al 261-115 1,934,667 11/1933 Harter 60-1 2,078,288 4/ 1937 Sherman 55-39 2,315,481 3/1943 Drewry 5539 2,566,732 9/1951 Krieg.

2,580,791 1/1952 Kahn 261-118 2,710,745 6/1955 Bunting 261-115 2,712,929 7/ 1955 Wilson 261-113 2,845,137 7/1958 Sebald 5554 2,865,827 12/1958 Dwyer 204-1932 2,900,792 8/1959 Buri 60-104 2,939,685 6/1960 Worn et al. 261-111 2,957,815 10/ 1960 Pacault et a1. 204-1932 2,963,872 12/1960 Latimer 6224 10 2,998,234 8/ 1961 Haseldon 261-113 3,009,325 11/1961 Pirsh -105 3,064,954 11/1962 Eckert 261-113 FOREIGN PATENTS 709,888 6/1954 Great Britain.

OTHER REFERENCES C. M. Leonard et al.: Heat Fundamentals N.Y., Pitrnan Publishing Corp., 1956, pp. 234, 238.

I. Gastpar: European Practice with Sulzer Monotube Steam Generators. In A.S.M.E. Transactions, Easton, Pa., The Mack Printing Co., vol. 775, p. 1358 (October 1953).

Virgil Faires: Thermodynamics of Heat Power, Macmillan Co., NY. (1958), p. 206.

William Severens et al.: Steam, Air, and Gas Power, John Wiley and Sons, NY. (1954), p. 181.

REUBEN FRIEDMAN, Primary Examiner.

HERBERT L. MARTIN, Examiner.

B. NOZICK, R. D. MULTER, Assistant Examiners. 

1. A STEAM SYSTEM COMPRISING A STEAM GENERATOR, A STEAM-UTILIZING APPARATUS, A CONDENSER, A DESUPERHEATERDEAERATOR MEANS AND A CONDENSATE STORAGE TANK CONNECTED IN SERIES BY CONDUIT MEANS IN CIRCUIT, A STEAM BYPASS CIRCUIT MEANS CONNECTED THROUGH A PRESSURE RESPONSIVE VALVE MEANS TO SAID CONDUIT MEANS INTERCONNECTING SAID STEAM-UTILIZING APPARATUS AND SAID STEAM GENERATOR, SAID STEAM BY-PASS CONDUIT MEANS COMMUNICATING WITH SAID DESUPERHEATER-DEAERATOR MEANS, SAID PRESSURE RESPONSIVE VALVE MEANS SO CONSTRUCTED SAID ARRANGED TO PERMIT THE FLOW OF STEAM FROM SAID STEAM GENERATOR TO SAID STEAM-UTILZING APPARATUS UNTIL THE PRESSURE OF SAID STEAM EXCEEDS A PRE-DETERMINED PRESSURE AND THEN TO DIRECT SAID STEAM THROUGH SAID STEM BY-PASS CONDUIT TO SAID DESUPERHEATER-DEAERATOR MEANS, SAID DESUPERHEATER-DEAERATOR MEANS COMPRISING A TANK HAVING A DEAERATING ZONE AND A DESUPERHEATING ZONE, SAID DESUPERHEATING ZONE BEING ABOVE SAID DEAERATING ZONE AND COMMUNICATING THEREWITH, A DEAERATED WATER OUTLET CONNECTED TO THE BOTTOM OF SAID TANK, MEANS FOR SPRAYING CONDENSATE FROM SAID CONDENSER INTO SAID DESUPERHEATING ZONE, SAID DEAERATING ZONE BEING BELOW SAID SPRAYING MEANS TO RECEIVE SAID CONDENSATE FROM SAID HIGH TEMPERATURE STEAM ZONE, MEANS FOR SUPPLYING STEAM TO SAID DEAERATING ZONE, SAID STEAM BY-PASS CONDUIT MEANS COMMUNICATING WITH SAID DESUPERHEATING ZONE AND STEAM OUTLET MEANS FOR REMOVING STEAM FROM SAID DESUPERHEATING ZONE AND SAID DEAERATING ZONE. 